Vantaggi
I've worked at two different properties - one full service, one select service. Most of my "pros" come from full service but some apply to both. Time off policies can be flexible depending on which department you work in. My experience has been in rooms division and there is a lot of flexibility in days off depending on your manager or who writes your schedule. Promotions came fairly quickly, with lots of opportunity for lateral moves to gain experience within the division, which can be helpful in moving up. The first property I worked at had a lot of leeway with budgeting, so they were able to do a lot of incentives and special events for their employees. Each property varies on this, but overall at the corporate level, they value their employees and strive to show this. Benefits are good, especially when it comes to staying at Hyatts around the world.
Svantaggi
Compensation is much better at full-service hotels (in my experience). Select service expects you to do so much more with less hours & fewer employees. Because there are fewer levels of management, each manager is expected to take on a lot more responsibility throughout the hotel. Leadership varies by property (obviously) and my experiences were better in full service. Because the hotel business is 24/7, expect to miss holidays and work crazy hours when you're starting out - or just starting a new position. Your friends with "banker's hours" jobs will NOT understand your schedule but there are plenty of new friends to be made in the industry who completely understand that sometimes an after work bite to eat comes at midnight.